How to Repair a Defective or Weak Cell in a 12-volt Battery

The 12-volt battery that is utilized in cars produces electrical energy after two chemical reactions. This battery constitutes of plates made out of lead and these are submerged in sulfuric acid. The plates need to be fully immersed in the electrolyte (sulfuric acid) for efficient results. Along with this, the electrolyte needs to be of the appropriate strength and the state of the plates is also a factor. Whether the electrolyte is lost or impurities make their way in or there is no regular charging, the existing chemical balance can be disrupted flawing its operation. In order to correct the battery’s operation, the chemical balance needs to be restored to its initial state.

The first step is to clean the top of the battery using a piece of dry cloth. The area around the vent caps should be cleaned with more care as you need to open them and any loose dirt will not aid the cause.

Next you need to unscrew all of the vent caps on top of the cells. You can do this by hand or even use a screwdriver if you want to. Make sure that the caps are kept safe. You must then make use of a flashlight to see the level of the electrolyte liquid inside each cell. The top of the metal plates should be immersed by about a quarter of an inch. If the cell has a lower depths of liquid, they are weak cells of the battery. To adjust the fluid, make use of battery water.

Then place the vent caps back on and put the battery up for charging. After a timespan of about 12 hours, if a cell persists to be out of order, take the vent caps off once again. Use goggles and gloves for this procedure. Dip a hydrometer inside each cell to measure the severity of the acid. 1.265 is the gravity of a completely charged battery and this value should not be out of the 0.05 difference in all cells. But if the difference is greater than 0.05, you need to add more acid to that cell keeping in mind the manufacturer’s directives.

After that charge the battery again and then test it in the same way. If a cell remains defective, sulfation is most likely the cause for it. Prolonged low specific gravity produces lead-sulfate crystals in the cell. In this scenario, it I best to take the battery to a technician who will recommend either repairing or replacing the battery.

Recommendation

Charge the battery spanning every two weeks for optimal results and minimize sulfation.

Make a habit of measuring electrolyte fluid levels before charging the battery.

Caution

Always make use of protective gear when handling battery acid as it corrodes.

Make sure your eyes and mouth are protected and safe from the poison of the battery electrolyte.